Re: (DQL) Expressiveness of Query Patterns

From: Deborah McGuinness (
Date: 12/04/01

unfortunately i will not be able to participate in today's conference call.

I just wanted to add one point onto this discussion.  I am in sympathy of
using DLs as the core upon which we are building DAML+OIL.
I do NOT however agree that it is as strong a limitation as at least I am
reading between the lines in the interchange below.
There has been some work on query languages in DLs in the past that goes
beyond the expressive power of the base DL language.
One early example (in 1984) focusing on retrieval is ARGON [1]- that language
went beyond the base DL language (which was extremely limited).
A more recent (1996) effort focusing on a query language [2] also goes beyond
the base DL language.  A limited version of this was implemented for classic.

[1]   Patel-Schneider, P., Levesque, H., Brachman, R., `ARGON: Knowledge
Representation meets Information Retrieval', Proceedings of the First
Conference on Artificial Intelligence Applications, Denver, CO, 1984. IEEE
Computer Society.

It is not clear to me that the query language needs to be as constrained as
the base representation language and I think it is not in the best interest of
the effort if the query language is that restricted.
I do not think sticking with the DL tradition requires this restriction and
there are long published examples that support this position.


Richard Fikes wrote:

> . I would prefer DAML+OIL development to be
> > continued in the DL tradition, and if the WebOnt initiative feels
> > that some other approach should be adopted, perhaps as an
> > alternative, then another, different, intiative be begun to
> > investigate that.
> Well, if the committee also feels that way, then indeed perhaps we (or
> I, at least) should move my efforts to design a query language for the
> Semantic Web to WebOnt.  I think if this committee confines itself to
> DL's, then it is at risk of losing its impact.  I thought that the
> charter of this committee was to design the DAML language and that the
> DAML language was to be a candidate standard semantic markup language
> for the Semantic Web.  Using the DL tradition as the core of the DAML
> language seems like a good idea and has resulted in a very elegant and
> powerful core language.  However, it seems to me to be standing the
> effort on its head to confine the further development of the language
> and in this case the development of a query language for DAML to
> concerns of the DL community.  I think the committee needs to continue
> to lead in the development of Semantic Web language development and that
> it would be a major mistake for the committee to hold on to decision
> criteria that are not in the best interests of Semantic Web
> development.  Such a position would indeed push the WebOnt initiative in
> the direction of developing alternative approaches, which I think would
> be extremely unfortunate for all of us who are invested in DAML
> development.
> > And
> > as for "logical completeness", I am not sure what you mean
> By logical completeness, I mean guaranteed to find all the answers.  Not
> all reasoners will be able to do so, and that shouldn't disqualify them
> from being used.
> I am out of time for now.
> Richard

 Deborah L. McGuinness
 Knowledge Systems Laboratory
 Gates Computer Science Building, 2A Room 241
 Stanford University, Stanford, CA 94305-9020
 (voice) 650 723 9770    (stanford fax) 650 725 5850   (computer fax)  801 705

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